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(Model.)

E. T. STARR. Dental Plugger. No. 229,769. Patented July 6,1880.

UNITED STATES PATENT OFFICE.

ELI T. sTAEE, OE PHILADELPHIA, PA., AssIeNoE To JAMES W. WHITE, JAMESOLAEENGE WHITE, AND HENRY M. LEWIS, TEUsTEEs.

,DENTAL PLUGGER.

SPECIFICATION forming part of Letters 'Patent No. 229,769, dated July 6,1880.

Application led April 24, 1880. (Model.)

To alt-,whom it ma/y concern:

Beit known that I, ELI T. STARR, of the city and county of Philadelphia,in the State of Pennsylvania, have invented certain new and usefulImprovements in Dental Pluggers, of which the following is aspecification.

My invention relates to the class of instrui ments used by dentists forimpacting the fill- AIO ings 'of teeth, commonly known as dentalpluggers,77 and pertains particularly to malletplug ers of the typewhich are operated entirelyby the movement of the hand, and which embodyin their organization a handle or casing, a tool-holder movable endwisetherein, a hammer or mallet acting upon the tool-holder by giving blowsupon its butt-end, an impelling-spring acting upon the hammer, anddevices for raising or separating the hammer and tool-holder and 'fortrippingl or releasing the hammer so as to permit it to give its blowsupon the tool-holder at the proper time.

Such an instrument is shown in Letters Patent ofthe United Statesgranted to James C. Dean July 11, 1865, reissued December 2l, 1875,lasilo. 6,817, and it is upon said Deans instrument more especially thatmy present invention is designed as an improvement.

The'object of my said invention is to provide` a" simple, easilyhandled, and eiiicient malletfplug'ger, which is capable of beingreadily adjusted to give blows of the desired force, and Whichmay beused either as an automatic mallet' orrhammer instrument to giverapidlyrepeated blows, or as a simple pressure-tool, as exigencyrequires.

Ior this "end my invention consists of certain new combinations ofdevices, which are recited at the'e nd of the specification.

In the accompanying drawings, which illustrate- Iny improvements asorganized in the best way now known to me, Figure l' is a longitudinalcentral section through the instrument, with the parts in their normalposition, and Fig. 2 is a view, partly in elevation and partly insection, the tool-holder being in position to receive a blowT from thehammer. Fig. 3 is a view of the instrument from the buttend, and Fig.l 4is al front or face view of a portion of the instrument.

Thehandleor casing` A of the instrument is preferably made of a singlestraight metallic piece or tube, and the lower end, which is the end tobe grasped by the fingers of the operator, is surrounded by a preferablyhard-rubber thimble or finger-piece, a, corrugated or grooved to afforda firm hold. A tool-holder, B, is fitted snugly in the casing A, and ispermitted endwise movement to alimited extent. The socket b, in thefront end of said toolholder, is tted with a female screw at its in-`ner termination, as usual, which receives the mal e-threaded end of theplugging-point B', so as to hold it securely in the socket of thetoolholder while the instrument is in use. rEhe screw-threaded socketalso permits easy and ready insertion and removal of the various pointsor tools commonly used with this class of pluggers.

An arm or extension, a', at tbe upper end of the casing A, projects atright angles to the longitudinal axis or bore of said casing. To theouter end of said arm a there is jointed a hammer-arm, C, carrying atits inner end a hammer, c, which normally lies just over the bore of thecasing A, at its butt-end, the object of which is, that when raised landtripped the said hammer, which is a rocking or vibrating one, moving inthe arc of a circle. may be forced down to give a blow upon the butt-endof the tool-holder B, projecting from said casing.

The hammer is held down upon the upper end of the casing by a U-shapedspring, D, and this spring is the impelling-spring of the rockinghammer. One end, d, of said spring is fastened to the extension-arm a ofthe casing, while the other end, d', is fitted to press upon the outeror upper surface ofthe hammerarm C, this end d' of the spring beingcapable of sliding upon the said hammer-arm when the hammer is rockedupon its pivot to give p a blow. Said impelling-spring -D has a curvedplate, E, secured to it at its outer curved side, and a set-screw, c,works through an opening in said plate, so as to bear upon the branch ofthe spring which its the hammer-arm, for the purpose of varying thetension or force of said spring, and thereby regulating the force of theblows delivered by the hammer.

The hammer is raised, uplifted, or rocked IOO upon its pivot against thetension of its impellng-spring by means of a pivoted latch or pawl, F,acted upon by a spring, f, to hold it to its work, the said pawlengaging with a lug or projection, c', on the face ot' the .hammer c.The said pawl is pivoted to a sliding cup or thimble, Gr, on the outsideof the casing A, and the said cup is connected with the toolholder B bymeans of a connecting screw or pin, g, which passes through the cup, aswell as through a longitudinal slot, a2, in the casing, into atransverse socket or opening, b', in the tool-holder.

With the end ofthe plugging-point against a resisting filling or tooth,pressure on thc casing causes said casing to move endwise on thetool-holder toward its iront end, which movement is permitted by thelongitudinal slot a2 in the casing. During the eiidwisc movement of thecasing on the tool-holder the hammer is held uplifted, raised, or awayfrom the casing, owing to the engagement of the end of the pawl F withthe lug or projection c on the face of the hammer. As the casing reachesthe end of its movement the butt-end of the tool-holder is exposedbeyond its end, ready to receive the blow of the hammer when tripped orreleased from the holding-pawl, which release is accomplished at themoment the buttend of the holder is protrnded from the buttend of thecasing, owing partly to the movement of the hammer on its pivot in thearc of a circle and partly to the action of the iiiclined surface of thepawl next the casing, the pawl being guided and kept in positionlaterally by suitable studs of the extension-arm, between which the pawlworks.

As soon as the hammer-lug and the holdingpawl are disengaged the hammeris forced quickly upon the butt-end of the holder and gives its blow.

When the blow is delivered the downward pressure upon the casing shouldcease, and said casing will then automatically be raised by the actionof a spiral spring, H, fitted within the cup G, connected with thetoolholder, as before mentioned, said spring acting at one end against ashoulder, h, within the cup, and at the other against a shoulder, h',formed upon the outside of the casing, or by the eXtensioii-arni a', therange ot' movement of the casing on the tool-holder being limited by theend of the longitudinal slot a2, formed in said casing, as beforedescribed. This action of the spring H brings the end ot the pawl Fagain beneath the lug c' on the hammer c, in readiness for anotheractuation of the instrument, owing to the outward movement of the casingon the tool-holder, the casing in its said movement carrying the hainmerwith it. and the pawl yielding for the passage of the hammer-lug pastit.

At the nose of the hard-rublier finger-piece or thmble a is aspring-button, I, carrying a pin, 1', which passes through an opening inthe 65 casin g and engages, when depressed by the iin ger, with anannular recess or groove formed in the tool-holder, the object of whichis'to render the tool-holder and casing rigid, so that the tool may beused as a pressure-pluggen I do not broadly claim a spring so organizedwith a inallet-plugger as to separate the hammer and tool-holderafterthe blow is struck, so as to bring the'parts into position for anew blow, as such organization is shown in Letters Patent N o. 58,133and No. 58,257. granted, respectively, to Chandler Poor and Chauncey M.Hooker in 1866; nor do I claim the springbnttoii arrangement at the noseof the casing, which adapts the instrument for use as apressure-plugging tool, as that is not my invention, it being an oldinstrumentality for the purpose; nor do I claim to be the progenitor ofthe type of niallet-plnggers to which my improvements especially belong,as instruments which are made to give their blows to impact the fillingsof teeth by pressure upon the point of the tool have long been in commonuse; nor do I broadly claim an instrument of the class to which minebelongs having in its organization a rocking or vibrating hammer raisedand tripped by a lifting pawl or catch and thrown down to give its blowby an impelling-spring, as that is old. The organization, construction,and mode of operation, however, of my iinproved instrument issubstantially different from anything which has preceded it, as far as lani aware.

It will, of course, be understood that the instrument is to be held inthe hand in the usual manner-that is, somewhat after the manner ofholding a pencil, the point of the plugging-tool being directed againstthe filling to be impacted.

I claim herein as of my own invention- 1. The combination, substantiallyas herein before set forth, of the casing, the tool-holder, the rockin gham mer or mallet movable around its pivot, and the latch or pawl,connected with the tool-holder outside the casing, provided with aninclined or cam edge next said casing and acting directly upon a lug onsaid hammer to hold it uplifted as the casing is moved downward over thetool-holder, whereby said latch is disengaged from said lug to allow thehammer to strike its blow partly by the movement of the hammer in thearc of a circle and partly by the action of the cam edge of the latchupon the casing of the instrument.

2. The combination, substantially as hereinbefore set forth, of thecasing, the tool-holder, the rocking hammer or mallet, the lifting-lugon said hammer, the impelling-spring, and the latch or pawl outside thecasing which acts directly upon said lifting-lug to hold said hammeraway from the tool-holder until tripped to permit the hammer to give itsblow.

3. The combination, substantially as herein- IOO IIO

before set forth, of the easing, the extension bent mpelling-spring, andthe plate and set- 1o or arm thereof, the hammer-arm pivoted to screwcarried thereby, for adjusting the tensaid extension, and the U-shapedimpellingsion or power of said spring. spring fixed at one end andacting upon the In testimony whereof I have hereunto sub- 5saidhammerarm atthe other, with the capacity scribed my name.

` of sliding slightly upon said arm to aeoommo- ELI T. STARR.

date its rocking movements. Witnesses:

4. The combination, substantially as herein- GEORGE P. MORGAN,

before set forth, of the rocking hammer, the WILLIAM H. GILBERT.

